#pragma once

#include "driver/i2c.h"
#include "hal/i2c_types.h"
#include <cstdint>

namespace gay_ipod {

/*
 * Convenience wrapper for performing an I2C transaction with a reasonable
 * preconfigured timeout, automatic management of a heap-based command buffer,
 * and a terser API for enqueuing bytes.
 *
 * Any error codes from the underlying ESP IDF are treated as fatal, since they
 * typically represent invalid arguments or OOMs.
 */
class I2CTransaction {
  public:
    static const uint8_t kI2CTimeout = 100 / portTICK_RATE_MS;

    I2CTransaction();
    ~I2CTransaction();

    /*
     * Executes all enqueued commands, returning the result code. Possible error
     * codes, per the ESP-IDF docs:
     *
     * ESP_OK Success
     * ESP_ERR_INVALID_ARG Parameter error
     * ESP_FAIL Sending command error, slave doesn’t ACK the transfer.
     * ESP_ERR_INVALID_STATE I2C driver not installed or not in master mode.
     * ESP_ERR_TIMEOUT Operation timeout because the bus is busy.
     */
    esp_err_t Execute();

    /*
     * Enqueues a start condition. May also be used for repeated start conditions.
     */
    I2CTransaction& start();
    /* Enqueues a stop condition. */
    I2CTransaction& stop();

    /*
     * Enqueues writing the given 7 bit address, followed by one bit indicating
     * whether this is a read or write request.
     *
     * This command will expect an ACK before continuing.
     */
    I2CTransaction& write_addr(uint8_t addr, uint8_t op);

    /*
     * Enqueues one or more bytes to be written. The transaction will wait for
     * an ACK to be returned before writing the next byte.
     */
    I2CTransaction& write_ack(uint8_t data);
    template <typename ...More>
    I2CTransaction& write_ack(uint8_t data, More... more) {
      write_ack(data);
      write_ack(more...);
      return *this;
    }

    /*
     * Enqueues a read of one byte into the given uint8. Responds with the given
     * ACK/NACK type.
     */
    I2CTransaction& read(uint8_t *dest, i2c_ack_type_t ack);

    /* Returns the underlying command buffer. */
    i2c_cmd_handle_t handle() { return handle_; }

    // Cannot be moved or copied, since doing so is probably an error. Pass a
    // reference instead.
    I2CTransaction(const I2CTransaction&) = delete;
    I2CTransaction& operator=(const I2CTransaction&) = delete;
  private:
    i2c_cmd_handle_t handle_;
};

} // namespace gay_ipod